Thread: Please help, trying to make plug for USB hub...

Originally Posted by kamlung

i am trying to make a plug for my USB hub... i have a few leftover plugs from a universal adapter i bought... can someone please verify the polarity of the leads???

the lead on the end is longer than the inner one (right one)... im assuming the longer one should be 5V+??? please verify... here is pic...

Youve got it all wrong.

In your picture, the bottom pins are connected to the barrel connector (That is the thing that goes into your device.)

You need a continuity tester to see which one of the bottom pins connects to the outside of the barrel, and the inside of the barrel. Then you must decide which one needs what depedning in your device.

Most devices, but it is NOT a rule, is that the inside of the barrel (usually called the pin) is positive, and the outside of the barrel (usually called the shield) is ground.

The connector in your picture could care less how much voltage you send through it, and where the positive and negative are connected to, only your device cares, and it cares a lot.

Michael

test with a multimeter.

Originally Posted by Pudge

test with a multimeter.

so i test continuity... place voltage on the outside barrel and see which lead that goes too???

yeah i know its a general rule that the outside of the barrell is ground... i just wish these plugs were as universal as they say...

Originally Posted by kamlung

so i test continuity... place voltage on the outside barrel and see which lead that goes too???

yeah i know its a general rule that the outside of the barrell is ground... i just wish these plugs were as universal as they say...

No, do not place voltage on the outside barrel.

Test the continuity to see which pin connectes to which part of the barrel.

Then, look on the cube that power the hub, the one that it came with, and if if it tells you where positive and negative go. Often times the cube has a funny C with a dot in it, and lines leading from the dot to one side of the picture, and a line leading from the C to the other side, and then they have a + or - next to the line. THat way you know which one, the dot is the pin, and the C is the shield, need + and which one needs -.

Michael

USB hub did not come with one.. and they don't make it anymore.. so thats why im trying to make it...

Originally Posted by kamlung

USB hub did not come with one.. and they don't make it anymore.. so thats why im trying to make it...

Then you have a problem.

Next thing to do is look on the hub for the C and dot I described. Some times it is on the label on the unit. Also, how do you know that it takes 5 volts, it might take more?

Michael

Originally Posted by Wiredwrx

Then you have a problem.

Next thing to do is look on the hub for the C and dot I described. Some times it is on the label on the unit. Also, how do you know that it takes 5 volts, it might take more?

Michael

most hubs take 5V... i rather underpower it first before i put more power to it...

Originally Posted by Wiredwrx

Also, how do you know that it takes 5 volts, it might take more?

Michael

Can you open the hub and take a look at the PCB? Look around the power input area on the PCB and see if the input voltage is silkscreened on there.